Biology - Parasites and Pathogens

Question 1

What is a disease

Answer 1

Condition that impairs the normal activity of an organism

Question 2

What is an infectious disease

Answer 2

cause by an agent that is passed from one organism to another

Question 3

How are infectious diseases spread in humans

Answer 3

touch, faeces, moisture droplets, blood transfusions, insects

Question 4

What is a non-infectious disease

Answer 4

Not a contagious disease, caused by lifestyle factors such as environmental toxins, nutrition, inheritance (genes)

Question 5

What are examples of non-infectious diseases

Answer 5

Cancer, diabetes, asthma

Question 6

What are some examples of infectious diseases

Answer 6

Ebola, Malaria, plague, measles

Question 7

Define emerging diseases

Answer 7

Infectious disease that has increases in the past 30 years (Ebola)

Question 8

Define re-emerging diseases

Answer 8

Infectious disease that was once major world-wide, then declined and now has come back

Question 9

Causes of disease symptoms

Answer 9

Physical or chemical damage to a host organism, insufficient supply of necessary requirements, inappropriate response of organism to an environmental factor

Question 10

What does a parasite do

Answer 10

• Lives on or in another organism (host)
• Obtains food & shelter from host
• Adapted to particular host species
• host is harmed someway by this relationship

Question 11

In parasitism, is the host harmed

Answer 11

Yes by the symbiont, causing a disease

Question 12

Define primary host

Answer 12

It is the definitive host, when it reaches mature form (adult)

Question 13

Define secondary host

Answer 13

Infected by the larval stages of parasite

Question 14

Define vector

Answer 14

Organism that transports parasite from one host organism to another

Question 15

An example of an organism and its primary and secondary host

Answer 15

Primary host for malarial protozoan parasite, Pasmodium, is a mammal.
Secondary host is mosquito

Question 16

Examples of vectors

Answer 16

Insects that feed on infected animal or plant, which then transfer some parasites to next animal they feed on

Question 17

Life cycle of parasites - what are these characteristics

Answer 17

Patterns of structural, functional and behavioral adaptations

Question 18

Whats the attachment and establishment

Answer 18

when parasites require a means of attachment to their host

Question 19

Define ectoparasites

Answer 19

attach to external surface of host, using hooks and suckers

Question 20

Define endoparasites

Answer 20

located internally such as in gut or tissues of body

Question 21

What are the patterns of reproduction in parasites

Answer 21

• produce millions and millions of offspring, to increase chance that some will find new host
• many are hermaphrodites (both eggs and sperm)

Question 22

Why is timing and coordination important

Answer 22

A fertilised egg must be in right place at right time to be able to enter right host

Question 23

Example of good timing

Answer 23

production of malaria gametes is also synchronised and mature gametes are released from blood cells into blood plasma at same time of say that host species of mosquito feeds.

Question 24

What are the two different types of transmission that occurs between hosts

Answer 24

Passive and active transmission

Question 25

What’s an example of passive transfer

Answer 25

Parasite plays no active part in the transfer

E.g. Occurs when egg or larval stage is eaten by new host

Question 26

Whats active transmission

Answer 26

Larval stage of parasites actively seek out and attaches to new host.

Question 27

Why is nutrition important

Answer 27

Is what drives the relationship between parasites and host. Parasites obtain nutrients from their host, using specialised organs

Question 28

Whats the reduction of systems

Answer 28

Particularly endoparasites, show a reduction of the body-systems that have become unnecessary to them

Question 29

Define pathogenic organism

Answer 29

causes disease to another organism, many parasites are pathogenic (fungi)

Question 30

Bacteria structure

Answer 30

Prokaryotic cell, without a membrane-bound nucles and few organelles.

Question 31

Features of bacteria

Answer 31

Found almost everywhere, reproduce very rapidly (complete reproductive cycle in about 20 minutes) -Asexual

Question 32

List the characteristics of protozoans

Answer 32

• unicellular, eukaryotic organisms, reproduce both sexually and asexually, cause diseases such as malaria, sleeping sickness